… 6M, the query time dropped to ~40s. So the maximum possible benefit is when size of both the buffers is increased appropriately. Also… and that is ‘Handler_mrr_init’. Is it because of this that the query on MariaDB 5.5 is slow as compared to MySQL 5.6. Next interesting thing are the last two columns of the table above and…
Comment: Percona Toolkit 2.1 with New Online Schema Change Tool
April 22, 2012 By 9 Comments
… made the MySQL, apache2 and php updates available to Debian Squeeze avalable on DotDeb.org, and I find my qps dropping by 2/3 – with no changes to what is happening on the server. Any ideas on what is happening here… this is happenign, and if it is happening across the board to everyone? Have some updates made to INNOdb tables really slowed down mySQL as…
Post: Slow DROP TABLE
June 16, 2009 By 21 Comments
… LOCK_open is locked, no query can be executed because they are stopped from accessing any table. Here is when the slow file removal… removals much more efficiently: EXT3 mysql> drop table large_table; Query OK, 0 rows affected (7.44 sec) XFS mysql> drop table large_table; Query OK, 0 rows…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…MySQL manual, especially the option and variable reference table…drop_eventblogpercona.commanual Com_drop_functionblogpercona.commanual Com_drop_indexblogpercona.commanual Com_drop_procedureblogpercona.commanual Com_drop_serverblogpercona.commanual Com_drop_tableblogpercona.commanual Com_drop…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
…is fine, and the client has asked me to figure out why the website is slow…tables, I’ll paste in mysql> show global variables like ‘%table_size%’; +———————+———–+ | Variable_name | Value | +———————+———–+ | max_heap_table_size | 268435456 | | tmp_table…
Post: Why MySQL could be slow with large tables ?
June 9, 2006 By 139 Comments
… by serve drop in performance. This especially apples to index lookus and joins which we cover later. As everything usually slows down… of few large tables, which is completely disk bound can be very slow. One of the reasons elevating this problem in MySQL is lack of… to large tables Joining of large data sets using nested loops is very expensive. Try to avoid it. Joins to smaller tables is OK…
Post: Thinking about running OPTIMIZE on your Innodb Table ? Stop!
December 9, 2010 By 13 Comments
…mysql> alter table a drop key c; Query OK, 0 rows affected (0.46 sec) Records: 0 Duplicates: 0 Warnings: 0 mysql> optimize table a; +——–+———-+———-+——————————————————————-+ | Table…
Post: MySQL extensions for hosting
April 24, 2008 By 11 Comments
…candidates for dropping. All the…slow log live, but that is a bit ugly solution. That is where this patch can be very useful. With simple MySQL…: 0 mysql> SHOW TABLE_STATISTICS LIKE ‘hosting2%’; +——————————–+———–+————–+————————-+ | Table | Rows_read…
Post: Is your server's performance about to degrade?
May 18, 2010 By 13 Comments
…is important to know. Add just a bit more data, or add a bit more load, and suddenly things can drop… the slow query log: there are just places where the log is…; and Statistics; and similar no-tables, no-storage-engines queries are… that’s where improvements to the MySQL source code are necessary. But…
Post: MySQL Server Memory Usage
May 17, 2006 By 18 Comments
…operation to swap seriously slowing down. On now…table_size is rather maximum amount of memory MySQL will allocate for this operation. Note it is…is large enough to contain largest record in the given table which is held until table is…drop me a note if you have something to add). But the main point is…
